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Significance level test [1]
The way to reject the null hypothesis, based on the significant evidence against the hypothesis.
In practice, a significance level of 0.05 or 0.01 are chosen. For example, α=0.05 means that we are 95% confident that we have made the right decision.
Reject the hypothesis if the normalized z score lies outside the critical interval in the following table:

Level of significance, α

0.1

0.05

0.01

0.005

Critical interval, one-tailed

z<1.28

z<1.645

z<2.33

z<2.58

Critical interval, two-tailed

|z|<1.645

|z|<1.96

|z|<2.58

|z|<2.81

Accept the hypothesis otherwise (or, if desired, make no decision at all).